Magnetic ski bindings



July 25, 1967 K p, ROSENBERG 3,332,695

MAGNETIC SKI BINDINGS Filed Jan. 26. 1965 United States Patent 3,332,695 MAGNETIC SKI BINDINGS Kenneth I. Rosenberg, 1301 Grant Ave.,

Novato, Calif. 94947 Y Filed `lan. 26, 1965, Ser. No. 428,124 5 Claims. (Cl. 2S0-11.35)

The present invention relates to ski bindings and more particularly to safety ski bindings employing magnetic latching means.

The ideal ski binding is one which secures the skiers boot to the ski in a manner which prevents all relative movement therebetween until the skier falls at which time the binding completely releases Vthe boot from the ski. For downhill skiing purposes it is essential for the skiers boot to be securely held to the ski so that the ski and boot are integral. Only in this way can the skier apply his weight to the ski for controlling the direction of the skis. When a binding fails to so secure a boot to the ski and relative movement between the boot and the ski, such as heel lift, is allowed, the skiers ability to control his skis is impaired and the binding fails to perform a vital function. It is not uncommon for expert skiers to strap their boots directly onto their skies to absolutely prevent relative motion between the ski and the boot. In doing so, however, they completely abandon the safety feature of a ski binding which releases the boot when the skier falls.

The Wide variety of available ski bindings which are sold and used by skiers throughout the world evidences the fact that no single safety ski binding now known in the art functions in the ideal manner described above.

Most safety ski bindings include several hinged members and at least one spring member. These bindings allow heel lift, and are subject to malfunction due to the introduction of snow and ice during operation. Ski bindings of this general description are not easily operated under any conditions and are often very difficult to operate in the adverse conditions which exist on the slopes of a mountain. Thus a fallen skier who tries to re-secure his boots to his skis while on a slope is often confronted with a frustrating task.

Some ski bindings require special brackets and plates to be secured to the skiers boots thus preventing the skier from using those boots with any other type of ski binding. Other ski bindings not only require modification to the boot but also place unusual forces on the boot and thus greatly reduce the life of the boot.

The present invention teaches a ski binding which securely holds the skiers boot to the ski, releases the boot when the skier falls, regardless of the direction of the fall, is easily operated, does not include complicated parts subject to malfunction, does not require modification of the skiers boot or place unusual strains on the boot, is long lasting and able to operate with all standard ski boots.

Further, the present invention teaches a ski binding employing a magnetic latching means.

In the present invention the skiers boot is secured to the face of the ski by means of a binding cable which grasps the heel of the skiers boot and forces it down onto the ski. A magnetic latching mechanism is connected to the cable and supplies the holding force. The latching mechanism is designed to supply a holding force which is variable to accommodate the varying needs of skiers of dilferent weight and skiing capabilities while the cable makes it possible for the binding to accommodate all standard ski boots. The magnetic latching mechanism is designed to have a minimum number of moving parts and be unaffected by the presence of ice or snow. The latching mechanism also operates without any springs which suffer relatively large parameter changes due to the varying temperature conditions which skiers encounter during skiing. Thus, when the binding as taught by the present invention is adjusted to provide a certain holding force this force will remain constant regardless of temperature conditions. The elimination of a spring as the main force producing means also eliminates heel lift which is characteristic of spring actuated safety bindings. The absence of heel movement is a result of the inverse square law under which the magnet operates: the magnetic attraction varies inversely as the square of the distance increases from the poles.

The present invention also teaches the use of a magnetic toe locator which is exceptionally advantageous when rebinding skis while on a slope.

Accordingly, it is an object of the present invention to provide an improved safety ski binding having all of the features desired of a ski binding.

A further object of the present invention is to provide a ski binding which secures the skiers boot to a ski in a manner which prevents relative movement therebetween but releases the boot completely when a force is applied to the binding which indicates that the skier is falling.

Further objects of the present invention include the provision of a ski binding which is simple in construction and not subject to malfunction due to the introduction of ice and snow, a ski binding which releases in response to the lapplication of a force greater than a preselected force regardless of the direction in which that force is applied, a magnetic latching means which eliminates the use of springs and a magnetic toe locator of a novel design.

Further objects and advantages of the present invention will be made apparent in the following specification wherein a preferred form of the invention is described by reference to the accompanying drawing.

In the drawing:

FIG. l is an isometric illustration of lthe ski binding of the present invention together with a boot just prior to the boot toe being located on the ski;

FIG. 2 is an enlarged view of the toe locator with certain portions shown in section;

FIG. 3 is a View similar to FIG. l but with the boot located on the ski; and

FIG. 4 is an enlarged view of the magnetic latching means in its latched condition with certain portions shown 1n section.

Referring now to FIG. l, a ski 11 is equipped with a safety Ibinding comprising a cable means 12, a magnetic latching means 13 and a toe locator 14, for releasably securing a boot 16. Cable means 12 includes a conventional ski binding cable 17 attached to the ski by means of cable guides 18 which prevent the cable from falling olf of the ski while allowing the cable to move longitudinally along the ski. The guides are disposed along the side edges of the ski at locations relative to toe locator 14 which position the cable for urging the boot downuardlly lso as to prevent the boot heel from lifting off of t es i.

To secure boot 16 to ski 1\1 the latching mechanism 13 is released and the cable 17 is urged toward the rear of the ski so that when the boot is initially located in the toe locator 14 the cable 17 completely surrounds the boot. The cable 17 is then urged against the heel of the boot 16 and the latching mechanism 13 closed drawing the cable 17 taut with a force which has been preselected to suit the particular skier.

When a skier falls, a force is applied through Ihis 'boot to the securing cable which directs the force to the latching mechanism. The force applied against the cable due to a fall exceeds any force applied against the cable during normal skiing conditions. Thus by adjusting the latching mechanism to open when normal skiing forces on the cable are exceeded, the binding is made to release the boot when the skier falls but hold the boot securely to the ski during normal skiing. Since the normal skiing forces applied against the cable vary with the Weight and skiing experience of each individual skier, the release force of a ski binding must be variable to operate properly for diferent skiers.

The toe locator 14 performs several functions. It lo- Cates' the boot on the ski relative to cable 17 to insure that the boot is secured to the ski with the same force each time the binding is operated. It acts as a reaction member to prevent the horizontal component of the force applied against the boot from changing the location of the boot on the ski. And it acts as a temporary binding to assist in putting on the ski.

The locating mechanism x14 (see FIG. 2) includes an L-shaped aluminum mounting bracket 21 secured to the ski as by screws 22. Secured to the upstanding portion of bracket 211 by stainless steel screw 23 is a cylindrical magnetic pole piece 24. Secured within the interior of pole piece 24 by screw 27 is a toroidal permanent magnet 26. The abutting relationship between magnet 26 and pole piece 24 operates to magnetize the pole piece and give it a polarity which is the same as the polarizing of the face of magnet 26 which it contacts. A concave pole piece 28 is secured to the opposing face of Imagnet 26, also by screw 27, and like pole piece 24, has a magnetic polarity consistent with the face of the magnet to which it is secured. The concave pole piece 28 is physically disposed within pole piece 28 but at a distance from all portions thereof so that there is no contact between the pole pieces. Since each pole piece is associated with a different face of magnet 26, they are of opposite polarity. The shape and placement of the pole piece operate to effectively place the opposite faces of the magnet in closer relationship to one another for more efficient flux linkage therebetween. The magnet 26 and pole pieces 24 and 28 thus constitute a magnetic circuit which directs flux from one face of magnet 26 to pole piece 24, from pole piece 24 to pole piece 28 (thorugh a small air gap), and through pole piece 28 to the opposite face of magnet 26.

Secured to the toe of boot 16 is a hemispherical -toe keeper 29 formed from a magnetic material. The dimensions of keeper 29 are made dependent on the radius of curvature of pole piece 28 and the diameter of pole piece 24. When toe keeper 29 is inserted into the locator 14 it contacts both pole piece 24 and pole piece 28 magnetically short circuiting the flux path therebetween, whereby the toe keeper is magntically held to the locator. The force with which keeper 29 is retained in locator 14 is a function of the size and strength of magnet 26 and the ux linkage between the pole pieces. The toe locator 14 thus provides more than a locator and reaction member. The force with which the toe keeper 29 is secured to the locator is sufficient to form a temporary binding between the boot and ski which greatly simplifies the task of rebinding skis on a slope.

The locator 14 and toe keeper 29 also cooperate to produce a force on the cable 17 whenever the toe of the boot is urged out of the locator, as when a skier falls. When the skier falls and the toe tends to disengage the locator 14 it is necessary, due to the spherical configuration of the locator and toe keeper, for the boot to move toward the back of the ski. This results in a force on the cable 17 which, as explained above, causes the latching mechanism 13 to release, thereby releasing the boot from the ski. In this way the binding responds to all forces caused by a fall, regardless of the direction or type of fall, to release the boot.

Referring now primarily to FIGS. 3 and 4, the magnetic latch mechanism 13 includes a first portion 36 which is immovably secured to the ski and a second portion 37 which is movably secured to the ski and designed to engage the first portion 36. The cable 17 connects to the second latching portion 37 and acts to transmit to the boot the force with which the second latching portion engages the first latching portion.

The first latching portion 36 includes a pole piece 38 having an upstanding front portion 39. Pole piece 38 is secured to the ski 11 by stainless steel screws 41 and acts as a mounting bracket for a permanent magnet 42. In order toprevent possible short circuiting of the magnetic circuit of the latch mechanism, it is advantageous to place a coating of epoxy sealant on the surface of pole piece 38 which surrounds magnet 42. The permanent magnet 42 provides the latching force for the binding of the present invention and is located and secured onto pole piece 38 by an aluminum clamping member 43. Clamping member 43 has a cylindrical body portion 44 which fits into the center opening of the permanent magnet 42 and an integral flange forming top member 46 which rests on the top surface of the magnet. When the body portion 44 of clamping member 43 is disposedV in the inner opening of annular magnet 42 andsecured to the pole piece 38 by a stainless steel screw 47 the magnet is automatically disposed in its proper location relative to the second latching portion 37.

The first portion 36 of latching member 13 as described above is seen to have no moving parts which can malfunction and has a potential service life which is virtually unlimited (the theoretical life of magnet 42 which is advantageously selected to be of the dustproof ceramic variety is something in the neighborhood of 600 years).

The second portion of magnetic latch 13 comprises a keeper plate 51 which is secured to an aluminum support arm 52 as by stainless steel screws 53. When the latch 13 is closed, the keeper plate 51, which is of a magnetic material, engages the upper surface 31 of upstanding portion 39 of pole piece 38. Since pole piece 38 contacts one face of magnet 42, it has the same magnetic polarity as that face. Flux thus passes from magnet 42 through pole piece 38 and back to magnet 42 after traversing a small air gap. When keeper plate 51 contacts surface 31, it assumes amagnetic polarity opposite to that of the face of magnet 42 with Which it is in facing relation. Keeper plate 51 thus becomes part of the magnetic circuit and is magnetically held to surface 31.

The keeper plate 51 has a central hole 54 Which is somewhat larger than the largest diameter of the flange of clamp member 46 and approximately coaxial there with when the latch is closed. In this Way it is possible for the keeper plate 51 to engage the pole surface 31 without interference from aluminum clamp member 43. The height of the upstanding portion 39 of pole piece 38 is approximately .015 of an inch greater than the height of the upper surface of vmagnet 42 whereby the keeper plate 51 and magnet 42 are not in physical contact. They are close enough however to insure a complete magnetic circuit. Thus, all of the force available from magnet 42 for holding keeper 51 is brought to bear on the surface 31.

The height of flange 46 is greater than the distance between the upper surface of magnet `42 and the keeper 51 when the latch is closed. Thus, the flange extends into the hole 54 in keeper 51 and forms a loose coupling therewith. This coupling performs the important function of preventing movement of the keeper in a direction transverse to the ski, when the latch is closed. By providing means at a distance from hinge 63 for preventing lateral movement of keeper 51, possible damage to the hinge is prevented, as is improper latch release.

To insure that the keeper plate 51 securely engages the surface 31, the screws 53 ido not force the keeper plate against the support arm but rather form a loose connection. This allows the plate to rock relative to the arm and thereby align itself with the surface 31 of the pole piece.

This loose connection between keeper 51 and arm 52 also enables the latch to be opened manually, as when a skier wishes to remove his skis. When one edge of keeper 51 is urged upwardly it is relatively easy to release the keeper from the pole piece 39. In fact, this operation is performed most advantageously with a ski pole, therebyY eliminating the need to bend over.

Referring to FIG. 4, the support arm 52 includes a generally horizontal portion 61 to which keeper plate 51 is secured as described above, and an integral downwardly angled portion A62 which is hingedly secured at its end to a bracket 63. Bracket 63 is secured to the upper surface of the ski between the pole piece 38 and toe locator 14. Accordingly, the second portion 37 of the magnetic latch 13 is movably secured to the ski 11 and thus can be positioned at a distance from the first portion 36 of the latch without being detached from the ski itself.

The cable 17 is connected to the arm 52 by a Vclevis 64 and a hook 66. The clevis 64 is hingedly secured to the arm 42 at a location near the point Where the horizontally extending portion 61 and downwardly angled portion 62 join. The portion of support arm 52 between the pin joint 67, which secures clevis 64 to arm 62, and the pin joint 68 which secures the end of arm 62 to bracket 63, forms a moment arm for moving plate 51. When a force is applie-d to the hook 66, it acts through the clevis and aforementioned moment arm to rotate arm 62 upwardly. Thus, the magnetic force which secures keeper plate 51 to pole piece 38 acts against forces from the cable which urge the hook 66 toward the back of the ski. The force established in cable 17 necessary to disengage keeper plate 51 from pole piece 38 is a function of the length of the moment arm (vertical distance between pin joint 67 and pin joint 68) and the angle of the clevis 64 when the latch is closed. Accordingly, the amount of force which must be applied to the cable 17 in order to break loose the latch 13 and release the boot 16 can be varied by simply varying the position of the pin joint 67. This is made possible by the holes provided in arm 52. Another adjustment which governs the amount of force necessary to release the binding is made possible by the threaded connection between the hook 66 yand clevis 64 whereby the initial tension placed on cable 17 can be adjusted.

One of the several oustanding features of the present invention is the complete elimination of any spring members. Springs necessarily change their characteristics when subjected to significant temperature variations, and in doing so change the holding force of the binding. This can result in premature release, or even Worse, failure to release, with resulting physical harm. The elimination of spring members also eliminates the initial movement necessary in a spring member before it can apply a force to release the binding. By obviating the necessity of an initial spring movement, unwanted heel lift, which has heretofore -been reluctantly accepted as a necessary part of almost all ski bindings, is eliminated.

In the present invention the latch 13 remains closed until the force applied through cable 17 to arm 62 is sufficient to disengage the keeper plate 51 from the pole piece 38 at which time the latch opens completely and the boot is released. At no time prior to complete release is there a member which extends or otherwise moves to allow the heel of the boot to rise. Another important feature of the present invention isthe relative simplicity of the design together with the complete elimination of all but two moving parts. Other than the pin joints 67 and 68 there are no moving parts which can become frozen or rendered inoperative due to the introduction of ice or snow.

What is claimed is:

1. A safety binding for releasably securing a ski boot to a ski comprising in combination:

a binding cable secured to the ski and operative when pulled to apply a force to the -boot which urges the boot against the ski; and

magnetic latching means secured to the ski and operatively associated with said cable, said means operative when closed to pull said cable and thereby urge the boot to the ski, and operative when open to release said cable from the boot whereby the boot is free to leave the ski wherein said latching means comprises in combination:

a magnetic pole piece secured to the ski;

a permanent magnet secured to said pole piece;

a keeper hingedly secured to said ski, Iconnected to said cable and disposed to engage and be magnetically held to said pole piece while pulling said cable, said keeper providing no pull on said cable when disengaged from said pole piece.

2. The binding of claim 1 wherein said keeper comprises a support arm of non-magnetic material hinged at one endrto the ski and hinged to said cable at a location remote from-the hinged end, Iand a keeper plate of magnetic material secured to said support arm and disposed 'to engage said pole piece.

3. The binding of claim 2 wherein said support arm has a plurality of different hinge locations for connection with said cable.

4. The binding of claim 2 wherein said keeper plate is loosely secured to said support arm for movement about a horizontal axis.

5. The binding of claim 2 further comprising means disposed at a distance from the hinged end of said arm for preventing lateral movement of said keeper plate when said keeper plate engages said pole piece.

References Cited UNITED STATES PATENTS 2,199,444 5/ 1940 Rauglas 280-11.35 2,276,826 5/ 1942 Crowther 2SC-11.35 2,742,250 4/ 11956` Cronberger 317-159 X 2,760,744 8/-1956 Watrous 317-159 X 2,947,563 8/1960 Stitt 317--159 X 3,095,210 6/1963` Hallam. 3,095,525 6/'1963y Hansen 317-159 3,165,328 `1/ 1965 Malone. 3,246,907 4/-1966 Chisholm. 3,251,607 5/ 1966 Wren.

FOREIGN PATENTS 1,171,212 9/ 1958 France.

BENJAMIN HERSH, Primary Examiner.

MILTON L. SMITH, Examiner. 

1. A SAFETY BINDING FOR RELEASABLY SECURING A SKI BOOT TO A SKI COMPRISING IN COMBINATION: A BINDING CABLE SECURED TO THE SKI AN OPERATIVE WHEN PULLED TO APPLY A FORCE TO THE BLOT WHICH URGES THE BOOT AGAINST THE SKI; AND MAGNETIC LATCHING MEANS SECURED TO THE SKI AND OPERATIVELY ASSOCIATED WITH SAID CABLE, SAID MEANS OPERATIVE WHEN CLOSED TO PULL SAID CABLE AND THEREBY URGE THE BOOT TO THE SKI, AND OPERATIVE WHEN OPEN TO RELEASE SAID CABLE FROM THE BOOT WHEREBY THE BOOT IS FREE TO LEAVE THE SKI WHEREIN SAID LATCHING MEANS COMPRISES IN COMBINATION: A MAGNETIC POLE PIECE SECURED TO THE SKI; A PERMANENT MAGNET SECURED TO SAID POLE PIECE; A KEEPER HINGEDLY SECURED TO SAID SKI, CONNECTED TO SAID CABLE AND DISPOSED TO ENGAGE AND BE MAGNETICALLY HELD TO SAID POLE PIECE WHILE PULLING SAID CABLE, SAID KEEPER PROVIDING NO PULL ON SAID CABLE WHEN DISENGAGED FROM SAID POLE PIECE. 